1. Field of the Invention
The invention relates in general to an apparatus for writing data to an optical storage media, and more particularly to an apparatus for writing data to an optical storage media and a servo control unit and a laser diode driver unit thereof.
2. Description of the Related Art
FIG. 1 shows the architecture of a conventional optical storage device. Referring to FIG. 1, the conventional optical storage device 100 includes a servo control unit 110, a laser diode driver unit 120 and a laser diode 130. The servo control unit 110 includes a modulation unit 111, a write strategy generation unit 113 and a control unit 115. The modulation unit 111 receives the data to be written to the disk 140, and modulates and then outputs the data. Usually, the adopted modulation method is the EFM (Eight-to-Fourteen Modulation). The write strategy generation unit 113 receives the modulated data and converts the modulated data into a plurality of current control signals for the laser diode according to the write strategy. The current control signals are outputted to the laser diode driver unit 120 through a cable with multiple channels. The control unit 115 controls the operations of the modulation unit 111 and the write strategy generation unit 113. The laser diode driver unit 120 includes a current generator 121. The current generator 121 receives the current control signals and thus generates a control current to control the writing operation of the laser diode 130.
However, with the progressing of the optical storage technology and the increasing of the data capacity of the optical storage media, the write speed and the internal data transmission speed of the optical storage device have to be increased correspondingly. Because the servo control unit 110 and the laser diode driver unit 120 are disposed on different circuit boards, as mentioned above, the servo control unit 110 needs to transmit a current control signal to the laser diode driver unit 120 through the cable with multiple channels. When the writing operation is performed, the current control signal pertaining to a multi-pulse signal may have signal distortions. Thus, the signal distortions and the slow transmission speed may seriously influence the writing quality.